From ea6fb41752dda2e450bd8a318c7400f8cfa9111e Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 23 Feb 2012 01:33:19 -0500 Subject: [PATCH] um: embed ->stub_pages[] into mmu_context seriously, kmalloc() for two-element array of pointers? Signed-off-by: Al Viro --- arch/um/include/asm/mmu.h | 2 +- arch/um/kernel/skas/mmu.c | 23 +++++------------------ 2 files changed, 6 insertions(+), 19 deletions(-) diff --git a/arch/um/include/asm/mmu.h b/arch/um/include/asm/mmu.h index 30509b9f37fd..53e8b498ebba 100644 --- a/arch/um/include/asm/mmu.h +++ b/arch/um/include/asm/mmu.h @@ -12,7 +12,7 @@ typedef struct mm_context { struct mm_id id; struct uml_arch_mm_context arch; - struct page **stub_pages; + struct page *stub_pages[2]; } mm_context_t; extern void __switch_mm(struct mm_id * mm_idp); diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c index 1aee587e9c5d..db2ef422c1b8 100644 --- a/arch/um/kernel/skas/mmu.c +++ b/arch/um/kernel/skas/mmu.c @@ -92,8 +92,6 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm) goto out_free; } - to_mm->stub_pages = NULL; - return 0; out_free: @@ -120,29 +118,20 @@ void arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm) if (ret) goto out; - pages = kmalloc(2 * sizeof(struct page *), GFP_KERNEL); - if (pages == NULL) { - printk(KERN_ERR "arch_dup_mmap failed to allocate 2 page " - "pointers\n"); - goto out; - } - - pages[0] = virt_to_page(&__syscall_stub_start); - pages[1] = virt_to_page(mm->context.id.stack); - mm->context.stub_pages = pages; + mm->context.stub_pages[0] = virt_to_page(&__syscall_stub_start); + mm->context.stub_pages[1] = virt_to_page(mm->context.id.stack); /* dup_mmap already holds mmap_sem */ err = install_special_mapping(mm, STUB_START, STUB_END - STUB_START, VM_READ | VM_MAYREAD | VM_EXEC | - VM_MAYEXEC | VM_DONTCOPY, pages); + VM_MAYEXEC | VM_DONTCOPY, + mm->context.stub_pages); if (err) { printk(KERN_ERR "install_special_mapping returned %d\n", err); - goto out_free; + goto out; } return; -out_free: - kfree(pages); out: force_sigsegv(SIGSEGV, current); } @@ -151,8 +140,6 @@ void arch_exit_mmap(struct mm_struct *mm) { pte_t *pte; - if (mm->context.stub_pages != NULL) - kfree(mm->context.stub_pages); pte = virt_to_pte(mm, STUB_CODE); if (pte != NULL) pte_clear(mm, STUB_CODE, pte); -- 2.20.1